MEDIA ALTERNATIF UBI CILEMBU UNTUK PEMBIAKAN LACTOBACILLUS PLANTARUM SEBAGAI BIOPRESERVATIF PADA TAHU

• Main Author: Erika
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/44759
• Institution: Institut Teknologi Bandung

Due to its high water content, wet food products such as tofu and wet noodle are perishable. To extend the shelf life, permitted preservatives can be added into those food products. However, these preservatives are often ineffective to those wet food products, so illegal addition of non-food grade substances with anti-microbial activities into those food products. Consequently, it is necessary to search new safe preservatives having antimicrobial activities. One of lactic acid bacteria, Lactobacillus plantarum was reported can produce secondary metabolite, plantaricin showing antimicrobial activities and a good candidate of a food biopreservative. Lactobacillus plantarum bacteria need growth media based on carbohydrates in order to grow well and produce plantarisin lot. Various growth media organic and non organic can be used. The aim of this research was to obtain suitable and cheaper growth medium for Lactobacillus plantarum potentially applied in production of biopreservative. The media were prepared from potato, sweet potatoes, banana and cassava and then tested as media for Lactobacillus plantarum growth. The optimum fermentation time was determined from bacterial growth curves plotting optical turbidity of fermentation media as time function. Supernatant containing plantaricin was prepared by centrifugation of culture and pH adjustment to 6 - 7. Antimicrobial activities of the supernatant was tested against Escherichia coli, Staphylococcus aureus, dan Aspergillus flavus applying disk diffusion method, while preservative effect on tofu were tested by means of total plate count calculation taking into account time and temperature storage variation. The results showed that the optimum fermentation time was 32 - 33 hours while sweet potatoes were the best alternative media. All supernatants showed antimicrobial activities against Escherichia coli, Staphylococcus aureus, dan Aspergillus flavus and able to extend the shelf life of tofu up to 3 days at room temperature and 11 days at refrigerator temperature(4 °C). In addition the tofu treated with these supernatant showed no organoleptic changes during storage. Based on overall results, it was concluded that Cilembu sweet potato is a suitable and cheaper media for Lactobacillus plantarum growth potentially applied in the production of biopreservative.